title: Crystal structure of the human short coiled coil protein and insights into SCOC-FEZ1 complex formation.
abstract: The short coiled coil protein (SCOC) forms a complex with fasciculation and elongation protein zeta 1 (FEZ1). This complex is involved in autophagy regulation. We determined the crystal structure of the coiled coil domain of human SCOC at 2.7 Å resolution. SCOC forms a parallel left handed coiled coil dimer. We observed two distinct dimers in the crystal structure, which shows that SCOC is conformationally flexible. This plasticity is due to the high incidence of polar and charged residues at the core a/d-heptad positions. We prepared two double mutants, where these core residues were mutated to either leucines or valines (E93V/K97L and N125L/N132V). These mutations led to a dramatic increase in stability and change of oligomerisation state. The oligomerisation state of the mutants was characterized by multi-angle laser light scattering and native mass spectrometry measurements. The E93V/K97 mutant forms a trimer and the N125L/N132V mutant is a tetramer. We further demonstrate that SCOC forms a stable homogeneous complex with the coiled coil domain of FEZ1. SCOC dimerization and the SCOC surface residue R117 are important for this interaction.
authors.affiliation: Department of Neurobiology, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany.
authors.forename: Caroline
authors.initials: C
authors.lastname: Behrens
authors.forename: Beyenech
authors.initials: B
authors.lastname: Binotti
authors.forename: Carla
authors.initials: C
authors.lastname: Schmidt
authors.forename: Carol V
authors.initials: CV
authors.lastname: Robinson
authors.forename: John Jia En
authors.initials: JJ
authors.lastname: Chua
authors.forename: Karin
authors.initials: K
authors.lastname: Kühnel
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry* / Q000378:metabolism; D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D018360:Crystallography, X-Ray; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs; D021381:Protein Transport; D016415:Sequence Alignment
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; C528597:FEZ1 protein, human; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C430910:SCOC protein, human